Sun furnace



p 17, 1963 HUGUES ROBERT PROTAT 3,

- CALLED PROTAT D'HAUTEVILLE SUN FURNACE Filed Sept. 18, 1958 2 Sheets-Sheet 1 My a C & K

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CALLED PROTAT DHAUTEVILLE SUN FURNACE Filed Sept. 18, 1958 2 Sheets-Sheet 2 lyj INVENTOR.

HUGUES ROBER PK TAT United States Patent 3,104,211 SUN FURNACE Hugues Robert Protat, called Protat dHauteville, 75 Rue Colbert, Casablanca, Morocco Filed Sept. 18, 1958, Ser. No. 761,804 Claims priority, application France Sept. 23, 1957 Claims. (Cl. 202-234) The present invention relates to a sun furnace for the distillation of sea Water, particularly to obtain fresh Water and to produce steam intended to actuate the most various machines.

One object of this invention is to provide a furnace which includes a horizontal frame, having a wide surface, disposed at some distance above the ground: the bottom of the frame is constituted by juxtaposed panels which can swivel downwards to allow the recovery of the deposit of salt; these panels eventually can be remote-controlled. The frame is surmounted by a wire netting in the meshes of which are placed, at regular intervals, convergent lenses having the suitable focal length; above these lenses are disposed slanting mirrors, preferably of an elongated shape, the greater dimension of which is orientated in the north-south direction.

The horizontal frame constituting the sun furnace proper is fed with sea water through fiumes, preferably cylindrical, which are connected with one side of the frame by a concrete diverging tube, eventually through suction pumps.

The steam thus produced is sucked in a wide expansion chamber, itself connected with the side of the frame oppoa site to the diverging tube and which extends in a converging nozzle feeding a condenser.

Pipes, preferably made of brass and interconnected so as to form a coil for the production of steam, are disposed on the bottom of the horizontal frame and form, at least partly, the longitudinm armature thereof. The steam produced by the coil supplies motive power to a steam power station which, in turn, feeds the auxiliary machines in the plant, particularly the condenser and the suction pumps.

A sun furnace according to the invention, having a great capacity, that is to say a large surface, is particularly suitable for constituting, in any coastal region favoured with an important and regular insolation, an energy source having a great capacity and a very low cost price. :In dry regions, this sun furnace constitutes a fresh water source of invaluable value, and particularly enables, owing to its high efficiency, to irrigate very large territories.

By way of example, a form of embodiment of a sun furnace according to the invention, and particularly intended for the production of fresh water, is described hereafter and schematically illustrated in the annexed drawing.

FIGURE 1 is a plan view diagrammatically illustrating the entire installation of the sun furnace.

FIGURE 2 is a partial section of FIGURE 1, taken on the line 11-11.

FIGURE 3 is a section of FIGURE 1 taken on the line III-Ill.

The plant schematically illustrated in FIGURE 1 essentially includes four juxtaposed cylindrical flumes a, preferably having a diameter of 4 meters; one end of the flumes is immersed in the sea and the other end is connected, through a suction pump 0, with a concrete diverging tube a; this tube a is connected with one side of the body proper of the sun furnace b, which is partly shown, in vertical section, in FIGURE 2.

The body b of the furnace slants slightly towards the sea, the slope being preferably of about 0.6%.

As shown in FIGURE 2, the body b is constituted by a horizontal frame of great surface, for instance in the 2 shape of a square having sides 200 meters long and sup ported, at some distance above the ground, by masonrywork b. This frame includes a metallic armature the longitudinal elements of which are U-girders j; flat transverse elements i and fare fixed on both sides of the girders j and form frames for juxtaposed metallic panels g, made of preferably stainless sheet steels. These panels can swivel round suitable hinges '(not shown) so as to be at will folded back below the horizontal frame of which they normally form the bottom, these panels being eventually remote-controlled. The upper face of each panel is entirely covered by a removable sheet made of a flexible material, for instance of a plastic material such as neoprene.

The vertical web of each U-girder j is formed by the superposition of pipes, preferably made of brass, brazed together and connected so as to form a coil of steam engine.

A wire netting having wide meshes c is suspended at a suitable distance above the upper face i of the frame. Biconvex converging lenses d are disposed in some of the meshes of this wire netting so as to form a regular network; the focal length of the lenses is to be equal to the mean vertical distance between said wire netting c and the horizontal frame 1', f; preferably this distance averages 15 mm. and there are 1600 lenses per square meter.

Above these lenses are fixed slanting plane mirrors e, having an elongated shape, for instance 25 m. by 0.15 In. with their greater dimension oriented along the northsouthdirection, the whole plant being also preferably orientated along said north-south direction. The slope of these mirrors is adjusted, preferably automatically, so that their angle with the vertical is always equal to one half the zenith distance of the sun.

The side of the horizontal frame opposite the diverging tube a is connected by a sill l with a large sized expan sion chamber k, which is greater than the frame and extends in .a concrete converging duct m. This duct opens directly into an ammonia refrigerator n which condensates the purified steam. The inner surfaces of the converging duct m, exposed to the action of the steam, are preferably sheltered with a coating of vinyl resin.

The sun furnace above described operates as follows: the sea water flows through the flumes a, at a speed of about 2 meters per second, at the rate of cubic meters per second approximately, and the diverging tube a spreads it in a liquid layer having a rather small thickness over the bottom 1 of the horizontal frame of body b. Each of the lenses d brings the region of the atmosphere neighbouring its focus .and the liquid layer surface at a temperature averaging 700 (3., thanks to what about 2 litres of water are vaporized per second. The energy thus recovered corresponds to about calories per second and per square meter of the surface of the body b.

This steam is sucked in the expansion chamber k from where the converging duct in leads it into the refrigerator n where this steam condensates.

As the salt-content of the layer exposed to evaporation in body b increases gradually, the saturation point is reached and salt settles upon the bottom of the horizontal frame.

This salt can be recovered in daylight, the mirrors e, horizontally disposed, acting as shielding screens, but this salt is preferably recovered by night: labourers get down in the space, enclosed by the masonry-works b, between the bottom of horizontal frame and the ground; they turn down the swivelling panels g, as indicated in FIGURE 2, and unfasten the removable sheets which .are covered with salt; small freight-cars h, preferably of the Decauville type, or endless bands make the removal of the salt thus recovered easier. Overflow valves, not shown, are disposed at the upper part of body b; in the event of a clogging produced by the salt, these valves start warning signals, by light or sound.

The sill l prevents the salt from passing into the expansion chamber k.

The steam formed in the coil constituted by pipes of girders j is used for the production of motive power, particularly in a steam power station (not shown) which feeds the various auxiliary machines in the plant, particularly the condenser 11 and the suction pumps.

The plant above described allows the generation of a power of about 50,000 HP. and the production of an amount of fresh water sufficient to irrigate about 150,000 hectares.

What I claim is:

1. A solar furnace for the distillation of sea Water and comprising a rectangular frame having a bottom and receiving sea water therein, said frame being supported above the ground with its longer axis being oriented along the north-south direction, said frame bottom being inclined toward the sea along the same north-south direction, a plurality of downwardly pivotable panels in said frame bottom, removable sheets of a flexible material mounted on the inner surfaces of said panels to facilitate the recovery of salt deposited thereon by removing said sheets from the panels, a wire netting above said frame, a plurality of bi-convex lenses mounted in said wire netting and having a focal length equal to the mean vertical distance between said wire netting and said frame, a plurality of elongated inclined reflecting surfaces pivotably mounted about their substantially horizontal longitudinal axes and oriented in the north-south direction so that the inclination of said reflecting surfaces with respect to the vertical can be adjusted to be equal to the half zenith distance of the sun on the side of the frame nearest to the sea, a diverging tube extending from one side of the frame toward the sea, a plurality of juxtaposed feeding flurnes extending from said diverging tube and having their outer ends immersed in the sea, suction pumps mounted within said flumes to draw sea water, through the diverging tube into a thin water layer on the bottom of the frame whereby the Water layer is at the focus of Said lenses and the concentration of solar energy thereon evaporates said water, a steam expansion chamber connected with said frame on the side thereof further from the sea, a sill between said expansion chamber and the frame to prevent salt deposited on said frame from passing into the expansion chamber, a conveyor nozzle extending from said expansion chamber to convey low pressure water vapor accumulated thereinoutwardly of the chamber, and a condensing device connected to said conveyor nozzle to receive water vapor therefrom.

2. A solar furnace for the distillation of sea water and comprising a rectangular frame having a bottom and receiving sea water therein, said frame being at least 200 meters long along one of its side and being supported above the ground with its longer axis being oriented along the north-south direction, said frame bottom being inclined toward the sea along the same -north-south direction, a plurality of downwardly pivotable panels in said frame bottom, removable sheets of a flexible material mounted on the inner surfaces of said panels to facilitate the recovery of salt deposited thereon by removing said sheets from the panels, a wire netting above said frame and parallel thereto, a plurality of bi-convex lenses mounted in said wire netting of about 1600 lenses per square meter and having a focal length equal to the mean vertical distance between said Wire netting and said frame so as to produce a concentration of solar energy at each focus of a lense having a temperature of about 700 C., a plurality of elongated inclined reflecting surfaces of about 25 meters long pivotably mounted about their substantially horizontal longitudinal taxes and oriented in the north-south direction so that the inclination of said reflecting surfaces with respect to the vertical can be adjusted to be equal to the half zenith distance of the sun on the side of the frame nearest to the sea, a diverging tube extending from one side of the frame toward the sea, a plurality of juxtaposed feeding flumes extending from said diverging tube and having their outer ends immersed in the sea, suction pumps mounted within said flumes to draw sea water therethrough at about cubic meters per second through said diverging tube into a thin water layer on the bottom of the frame whereby the water layer is at the focus of said lenses and the concentration of solar energy thereon evaporates about 2 liters of water per square meter of frame surface, a steam expans-ion chamber connected with said frame on the side thereof further from the sea, a sill between said expansion chamber and the frame to prevent salt deposited on said frame from passing into the expansion chamber, a conveyor nozzle extending from said expansion chamber to convey low pressure water vapor accumulated therein outwardly of the chamber, and a condensing device connected to said conveyor nozzle to receive water vapor therefrom.

References Cited in the file of this patent UNITED STATES PATENTS 283,003 McCarty Aug. 14, 1883 842,788 Huntoon Jan. 29, 1907 983,424 Brosius Feb. 7, 19l1 1,002,496 Campbell Sept. 5, 1911 1,302,363 Grah m Apr. 29, 1919 1,544,029 Nelson June 30, 1925 1,683,266 Shipm-an Sept. 4, 1928 1,989,999 Niederle Feb. 5, 1935 1,993,213 Gill Mar. 5, 1935 2,025,724 Clendenin Dec. 31, 1935 2,110,167 Northcutt et a1 Mar. 8, 1938 2,141,330 A'bbot Dec. 27, 1938 2,249,642 Turner July 15, 1941 2,342,062 Schenk Feb. 15, 1944 2,456,562 Lindsay Dec. 14, 1948 2,490,659 Snyder Dec. 6, 1949 2,609,337 Taylor et al. Sept. 2, 1952 2,636,129 Agnew Apr. 21, 1953 2,803,591 Coanda et a1 Aug. 20, 1957 2,902,028 Manly Sept. 1, 1959 FOREIGN PATENTS 8,318 Great Britain Apr. 14, 1908 840,926 France May 8, 1939 OTHER REFERENCES Ellis: Fresh Water From the Sea," 1954, pages 161- 168. 

1. A SOLAR FURNACE FOR THE DISTILLATION OF SEA WATER AND COMPRISING A RECTANGUAR FRAME HAVING A BOTTOM AND RECEIVING SEA WATER THEREIN, SAID FRAME BEING SUPPORTED ABOVE THE GROUND WITH ITS LONGER AXIS BEING ORIENTED ALONG THE NORTH-SOUTH DIRECTION, SAID FRAME BOTTOM BEING INCLINED TOWARD THE SEA ALONG THE SAME NORTH-SOUTH DIRECTION, A PLURALITY OF DOWNWARDLY PIVOTABLE PANELS IN SAID FRAME BOTTOM, REMOVABLE SHEETS OF A FLEXIBLE MATERIAL MOUNTED ON THE INNER SURFACES OF SAID PANELS TO FACILITATE THE RECOVERY OF SaLT DEPOSITED THEREON BY REMOVING SAID SHEETS FROM THE PANELS, A WIRE NETTING ABOVE SAID FRAME, A PLURALITY OF BI-CONVEX LENSES MOUNTED IN SAID WIRE NETTING AND HAVING A FOCAL LENGTH EQUAL TO THE MEANS VERTICAL DISTANCE BETWEEN SAID WIRE NETTING AND SAID FRAME, A PLURALITY OF ELONGATED INCLINED REFLECTING SURFACES PIVOTABLY MOUNTED ABOUT THEIR SUBSTANTIALLY HORIZONTAL LONGITUDINAL AXES AND ORIENTED IN THE NORTH-SOUTH DIRECTION SO THAT THE INCLINATION OF SAID REFLECTING SURFACES WITH RESPECT TO THE VERTICAL CAN BE ADJUSTED TO BE EQUAL TO THE HALF ZENITH DISTANCE OF THE SUN ON THE SIDE OF THE FRAME NEAREST TO THE SEA, A DIVERGING TUBE EXTENDING FROM ONE SIDE OF THE FRAME TOWARD THE SEA, A PLURALITY OF JUXIAPOSED FEEDING FLUMES EXTENDING FROM SAID DIVERGING TUBE AND HAVING THEIR OUTER ENDS IMMERSED IN THE SEA, SUCTION PUMPS MOUNTED WITHIN SAID FLUMES TO DRAW SEA WATER THROUGH THE DIVERGING TUBE INTO A THIN WATER LAYER ON THE BOTTOM OF THE FRAME WHEREBY THE WATER LAYER IS AT THE FOCUS OF SAID LENSES AND THE CONCENTRATION OF SOLAR ENERGY THEREON EVAPORATES SAID WATER, A STEAM EXPANSION CHAMBER CONNECTED WITH SAID FRAME ON THE SIDE THEREOF FURTHER FROM THE SEA, A SILL BETWEEN SAID EXPANSION CHAMBER AND THE FRAME TO PREVENT SALT DEPOSITED ON SAID FRAME FROM PASSING INTO THE EXPANSION CHAMBER, A CONVEYOR NOZZLE EXTENDING FROM SAID EXPANSION CHAMBER TO CONVEY LOW PRESSURE WATER VAPOR ACCULATED THEREIN OUTWARDLY OF THE CHAMBER, AND A CONDENSING DEVICE CONNECTED TO SAID CONVEYOR NOZZLE TO RECIEVE WATER VAPOR THEREFROM. 